The demand for high capacity rechargeable batteries is strong. Many applications, such as aerospace, medical devices, portable electronics, and automotive, require high gravimetric and/or volumetric capacity cells. Lithium ion battery technology demonstrated significant promises in this regard. However, the lithium ion technology is primarily based on graphite electrodes, which have a theoretical capacity of only about 372 mAh/g.
Silicon is an attractive insertion material for lithium and other electrochemically active ions. The theoretical capacity of silicon in a lithium ion cell has been estimated at about 4200 mAh/g. Yet silicon and some other high capacity electrode materials have not been widely used or commercially implemented. One of the main reasons is the substantial change in volume that silicon undergoes during cycling. Silicon swells by as much as 400% when it is charged close to its theoretical capacity. Volume changes of this magnitude can cause substantial stresses in the negative electrode and other internal cell structures resulting in fractures and pulverization, loss of electrical connections within the electrode, and capacity fade of the battery. One approach to addressing this issue involves the use of silicon nanostructures (e.g., silicon nanowires) as the negative electrode active material in lithium batteries. See e.g., Chan, C. K., et al., High-performance lithium battery anodes using silicon nanowires, Nature, Vol. 3, January 2008. The inventors have recognized that conventional lithium ion cell designs that include negative current collecting substrates such as rolled metallic foils, with low surface roughness, do not allow silicon nanostructures to realize their potential as high capacity electrode materials for lithium ion cells. Overall, there is a need for improved battery cell designs that can accommodate high capacity active materials, particularly nanostructured materials, in battery electrodes and minimize the drawbacks described above.